Mass flow verifiers (MFVs) are used to verify the accuracy of fluid delivery and measurement systems. Such systems include, for example, mass flow controllers (MFCs), mass flow ratio controllers (FRCs), and mass flow meters (MFMs) in semiconductor fabrication systems and other materials processing systems.
A semiconductor fabrication process can involve the delivery of several different gases and gas mixtures in various quantities over several processing steps. Generally, gases are stored in tanks at a processing facility, and gas metering systems are used to deliver metered quantities of gases from the tanks to processing tools, such as chemical vapor deposition reactors, vacuum sputtering machines, plasma etchers, etc. Other components, such as valves, pressure regulators, MFCs, FRCs, MFMs, MFVs, and the like can be included in the gas metering system or in a flow path from the gas metering system to a processing tool. Components such as MFCs, FRCs, MFMs, and MFVs are provided to ensure the precise delivery of process gases. As space is often at a premium in such processing systems it is desirable that components be as small or as space-efficient as possible.